Study of stable laser cavity with hole-coupling output mirror

A new type of CO₂ laser resonator with hole-coupling output is presented in this paper. The laser beam in the resonator is focused into the reflector assembly system composed of a reflector with a small central hole and an output mirror with a central coupling hole. According to the theory of diffraction optics, the laser optical field distribution in the cavity and the far-field distribution are analyzed by numerical calculation. In the experiment, the variations of the laser output power with continuous current discharged is measured. The maximum laser output power is 14.5W at the discharge current 12mA. The laser power distribution of the output beam at the distance of 1m is measured, and the result is in good accordance with numerical calculation. The laser cavity with hole-coupling can be used in intracavity pumped THz laser output and other types of intracavity pumped lasers.